Data centers with server farms are essential to the functioning of computer systems in different applications and sectors in the modern economy. Generally, server farms in data centers include a large number of servers that consume power during operation to process and handle jobs or computational tasks. These servers account for the major portion of energy consumption of data centers.
Since excessive power consumption in server farm may increase operation cost and cause environmental concerns, various approaches have been proposed to optimize energy utilization in server farms. In one example, speed scaling is applied to control server speed. In another example, right-sizing of server farms is applied by powering servers on/off according to traffic load.
Rapid improvements in computer hardware have resulted in frequent upgrades of parts of the server farms, and this has led to server farms with different computer resources (heterogeneous servers) being deployed. The heterogeneity of servers in server farm significantly complicates the optimization of energy utilization. Therefore, there remains a need for server farm designers and/or operators to devise an optimal strategy in operating and managing server farms so as to conserve energy and maximize the effective energy efficiency of server farms.